Irene had $315 more than Dana. Irene gave
23 of her money to Dana. Dana then gave 20% of her money to Irene. In the end, Dana had $139 more than Irene. How much did Irene have at first?
| |
Irene |
Dana |
Comparing Irene
and Dana at first |
315 more |
|
| Before |
3 u |
+ 315 |
3 u |
|
| Change 1 |
- 2 u |
- 210 |
+ 2 u |
+ 210 |
| After 1 |
1 u |
+ 105 |
5 u |
+ 210 |
| Change 2 |
+ 1 u |
+ 42 |
- 1 u |
- 42 |
| After 2 |
2 u |
+ 147 |
4 u |
+ 168 |
23 x 315= 210
315 - 210 = 105
20% x 5 u
=
20100 x 5 u
= 1 u
20% x 210
=
20100 x 210
= 42
210 - 42 = 168
105 + 42 = 147
If Irene received another $139 in the end, Irene and Dana would have the same amount of money.
4 u + 168 = 2 u + 147 + 139
4 u - 2 u = 147 + 139 - 168
2 u = 118
1 u = 118 ÷ 2 = 59
Amount that Irene had at first
= 3 u + 315
= 3 x 59 + 315
= 177 + 315
= $492
Answer(s): $492
